title: Genetic diversity of transmission blocking vaccine candidate (Pvs25 and Pvs28) antigen in Plasmodium vivax clinical isolates from Iran.
abstract: The leading candidates for a Transmission Blocking Vaccine (TBV) in Plasmodium vivax parasite are the ookinete surface protein 25 (Pvs25) and Pvs28, which their phase I clinical trial is ongoing. Therefore, we carried out survey of polymorphisms of the pvs25 and pvs28 genes in P. vivax populations that are circulating in the two malaria areas of contrasting endemicity in Iran, before field application of the TBV. To characterize the polymorphisms of pvs25 and pvs28 genes, 50 isolates were analyzed by sequencing method and their gene structure was compared with parasite populations from India, Bangladesh, Indonesia, Thailand, Mexico and Brazil. Three mutations were detected in pvs25 and pvs28 including Q87K, E97Q, I130T and M52L, T65K, T140S with two and four distinct haplotypes, in comparison with the Sal I sequence type, respectively. Both haplotypes of Pvs25 were found among northern and southern P. vivax isolates; however, only two and three of the Pvs28 variants were observed among the northern and southern isolates, respectively. In conclusion, the present results show the limited sequence polymorphism of the pvs25 and pvs28 genes among field P. vivax population in Iran. These results highly encourage with respect to applicability of Pvs25 and Pvs28-based vaccine against P. vivax infection in the region, where these parasites are prevalent, whether these occur in the temperate or tropical zones.
authors.affiliation: Malaria and Vector Research Group (MVRG), Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran. zakeris@yahoo.com
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Zakeri
authors.forename: Sepand
authors.initials: S
authors.lastname: Razavi
authors.forename: Navid Dinparast
authors.initials: ND
authors.lastname: Djadid
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics*; D000954:Antigens, Surface / Q000737:chemistry / Q000235:genetics*; D002986:Clinical Trials as Topic; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D006239:Haplotypes; D006801:Humans; D007492:Iran; D017780:Malaria Vaccines / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D016780:Malaria, Vivax / Q000276:immunology / Q000469:parasitology*; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010966:Plasmodium vivax / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D016054:DNA, Protozoan; D017780:Malaria Vaccines; C121473:Pvs25 protein, P vivax; C121474:Pvs28 protein, P vivax